A terbium o-methylbenzoate complex with 1,10-phenanthroline, Tb(o-MBA)_3phen(where o-MBA = o-methylbenzoate and phen = 1,10-phenanthroline) was prepared from ethanol solutionand its crystal structure was determined by...A terbium o-methylbenzoate complex with 1,10-phenanthroline, Tb(o-MBA)_3phen(where o-MBA = o-methylbenzoate and phen = 1,10-phenanthroline) was prepared from ethanol solutionand its crystal structure was determined by X-ray diffraction. The crystal of the complexTb(o-MBA)_3phen belongs to triclinic crystal system and P1 (#2) space group. The crystal data are asfollows: a = 1.4371(4) nm, b = 1.7387(2) nm, c = 1.3109(2) nm, α = 96.37(1)°, β = 107.21(2)°,γ= 82.78(2)°, Ⅴ= 3.094(1) nm^3, Z= 2, M_r = 1489.12, D_c= 1.598 g·cm^(-3), μ = 2.330 mm^(-1)and F(000) = 1488.00. The final R and R_w are 0.038 and 0.047 for 8668 [Ⅰ > 2σ(Ⅰ)] uniquereflections, respectively. In the complex each Tb^(3+) ion is eight-coordinated by one1,10-phenanthroline molecule, one bidentate carboxylate group and four bridging carboxylate groups.The carboxylate groups are bonded to the terbium ion in two modes: the chelating bidentate and thebridging bidentate. Excitation and luminescence data observed at room temperature show that thetitle complex emits strong green fluorescence under ultraviolet light. The results of thermalanalysis indicate that the complex Tb(o-MBA)_3phen is quite stable to heat.展开更多
Understanding electronic structure is crucial to enhance the battery performance. Soft X-ray spectroscopy(SXS) is one of the most effective methods to provide direct probe of electronic states. Here, spectroscopic mea...Understanding electronic structure is crucial to enhance the battery performance. Soft X-ray spectroscopy(SXS) is one of the most effective methods to provide direct probe of electronic states. Here, spectroscopic measurements of transition metal 3 d and oxygen 2 p states are simply reviewed. Then, we mainly focus on the perspective of the development direction of modern SXS techniques. Although the true power of recently developed high efficiency mapping of resonant inelastic X-ray scattering(m RIXS) has been apparent for materials and chemistry studies, great challenges remain for mRIXS spectroscopic interpretation, and the understanding of the battery materials on novel redox activities remains elusive.展开更多
Structural and magnetic properties are investigated for Fe1-xMnxV2O4 （0≤ x ≤ 1） spinels. As orbital-active Fe^2＋ is substituted with Mn^2＋, the cubie-to-tetragonM transition TsI and the tetragonal-to-orthorhombi...Structural and magnetic properties are investigated for Fe1-xMnxV2O4 （0≤ x ≤ 1） spinels. As orbital-active Fe^2＋ is substituted with Mn^2＋, the cubie-to-tetragonM transition TsI and the tetragonal-to-orthorhombic transition Ts2 gradually decrease. These structural transitions originate from the Fe^2＋ ferro-orbital order （F-OO）. Below Yafet-Kittel （YK） magnetic transition TN2, V^3＋ orbital order （V-OO） plays an important role on global structure. Here x = 0.6 is a critical point. Fe^2＋ F-OO and V^3＋ F-OO coexist for 0 ≤ x ≤ 0.5. For x≥ 0.6, the orbital pattern of V^3＋ is antiferro （AF）-00, and Fe^2＋ F-OO disappears. Structural transition Ts3, accompanied by YK magnetic transition TN2, decreases initially, and then increases at x = 0.6. A scenario for the complex phase diagram arising from the cooperation or competition of Fe^2＋ and V^3＋ orbitals is proposed.展开更多
We investigate the electronic structures and phase stability of ZnO, CdO and the related alloys in rocksalt（B1）and wurzite（B4） crystal, using the first-principle density functional theory within the hybrid functio...We investigate the electronic structures and phase stability of ZnO, CdO and the related alloys in rocksalt（B1）and wurzite（B4） crystal, using the first-principle density functional theory within the hybrid functional approximation. By varying the concentration of Zn components from 0% to 100%, we find that the Zn_xCd（1-x）O alloy undergoes a phase transition from octahedron to tetrahedron at x = 0.32, in agreement with the recent experimental findings. The phase transition leads to a mutation of the electron mobility originated from the changes of the effective mass. Our results qualify Zn O/Cd O alloy as an attractive candidate for photo-electrochemical and solar cell power applications.展开更多
To determine the structure of o-methylisourea for instructing its application and factory production, crystalline o-methylisourea hydrosulfate was synthesized in this paper by methylation of urea with dimethylsulfate,...To determine the structure of o-methylisourea for instructing its application and factory production, crystalline o-methylisourea hydrosulfate was synthesized in this paper by methylation of urea with dimethylsulfate, followed by acidification in 53% yield. Its single crystal prepared from 95% ethanol is determined by X-ray diffraction analysis. The crystal is of monoclinic, space group P21/c with a = 8.5330（10）, b = 7.0548（9）, c = 11.6764（14） A°, β = 95.429（2）°, Mr = 172.16, V= 699.75（15）A°^3, Dc = 1.634 g/cm^3, Z = 4, F（000） = 360 andμ（MoKα） = 0.435 mm^-1. Of 1511 unique reflections, 1294 is gotten （I 〉 2σ（I））. The structure was solved by Fourier method and refined to R = 0.0438 and wR = 0.1209. The crystal structure shows that o-methylisourea combines with bisulfate via the intramolecular hydrogen bond between N（2）-H（4） of o-methylisourea and O（2） of bisulfate. As a result, the molecular structure is [H2NC（OCH3）NH2]HSO4 and the formula is C2H8N2O5S or C2H7N2O·HSO4 but not H2NC（OCH3）NH-HSO4 or H2NC（OCH3）NH·0.5H2SO4.展开更多
In this paper, 5＇-O-tosyl-2,3＇-anhydrothymidine has been synthesized and its crystal structure was analyzed. The crystal belongs to the triclinic system, space group P1, with a = 5.397（2）, b = 6.1886（18）, c = 3....In this paper, 5＇-O-tosyl-2,3＇-anhydrothymidine has been synthesized and its crystal structure was analyzed. The crystal belongs to the triclinic system, space group P1, with a = 5.397（2）, b = 6.1886（18）, c = 3.507（5）A, α = 87.74（2）,β = 89.84（4）,γ = 73.79（2）°, C17H18N2O6S, Mr = 378,39, Z = 1, V = 432.8（3）A^3, Dc = 1.452 g/cm^3, F（000） = 198 and Flack = -0.11（14）. No intermolecular hydrogen bonds exist in the crystal, and the angle between benzene ring and pyrimidine planes is 32.23°.展开更多
The building block of N-alkyl derivative of allosamidin（chitinase inhibitor）,4,6-O-benzylidene-N-octyl-D-allosamine hydrochloride was stereoselectively synthesized in two steps under mild conditions.Nucleophilic add...The building block of N-alkyl derivative of allosamidin（chitinase inhibitor）,4,6-O-benzylidene-N-octyl-D-allosamine hydrochloride was stereoselectively synthesized in two steps under mild conditions.Nucleophilic addition of octylamine to 2- oxoglucopyranoside gave a‘carbonyl group transfer＇ product in 62%yield.Subsequent stereoselective reduction of newly formed C=O with NaBH_4 produced title compound in 75%yield.X-ray diffraction analysis indicates the title compound adopts syn 1,2,3 stereochemistry and chair-chair conformation.The crystal structure is stabilized by hydrogen bonds.展开更多
The splitting of potential energy levels for ground state X^2∏g of O^x2 （x = ＋1,-1） under spin-orbit coupling （SOC） has been calculated by using the spin-orbit （SO） multi-configuration quasi-degenerate perturb...The splitting of potential energy levels for ground state X^2∏g of O^x2 （x = ＋1,-1） under spin-orbit coupling （SOC） has been calculated by using the spin-orbit （SO） multi-configuration quasi-degenerate perturbation theory （SO-MCQDPT）. Their Murrell-Sorbie （M S） potential functions are gained, and then the spectroscopic constants for electronic states 2^∏1/2 and 2^∏3/2 are derived from the M S function. The vertical excitation energies for O^x2 （x = ＋1,-1） are v[O2＋1^（2∏3/2→X^2∏1/2）] =195.652cm^-1, and v[O2^-1（2^∏1/2 →X^2∏3/2）] =182.568cm^-1, respectively. All the spectroscopic data for electronic states 2^∏1/2 and 2^∏3/2 are given for the first time.展开更多
基金The project is financially supported by the Natural Science Foundation of Hebei Province (No. 202140 and No. 203148)
文摘A terbium o-methylbenzoate complex with 1,10-phenanthroline, Tb(o-MBA)_3phen(where o-MBA = o-methylbenzoate and phen = 1,10-phenanthroline) was prepared from ethanol solutionand its crystal structure was determined by X-ray diffraction. The crystal of the complexTb(o-MBA)_3phen belongs to triclinic crystal system and P1 (#2) space group. The crystal data are asfollows: a = 1.4371(4) nm, b = 1.7387(2) nm, c = 1.3109(2) nm, α = 96.37(1)°, β = 107.21(2)°,γ= 82.78(2)°, Ⅴ= 3.094(1) nm^3, Z= 2, M_r = 1489.12, D_c= 1.598 g·cm^(-3), μ = 2.330 mm^(-1)and F(000) = 1488.00. The final R and R_w are 0.038 and 0.047 for 8668 [Ⅰ > 2σ(Ⅰ)] uniquereflections, respectively. In the complex each Tb^(3+) ion is eight-coordinated by one1,10-phenanthroline molecule, one bidentate carboxylate group and four bridging carboxylate groups.The carboxylate groups are bonded to the terbium ion in two modes: the chelating bidentate and thebridging bidentate. Excitation and luminescence data observed at room temperature show that thetitle complex emits strong green fluorescence under ultraviolet light. The results of thermalanalysis indicate that the complex Tb(o-MBA)_3phen is quite stable to heat.
文摘Understanding electronic structure is crucial to enhance the battery performance. Soft X-ray spectroscopy(SXS) is one of the most effective methods to provide direct probe of electronic states. Here, spectroscopic measurements of transition metal 3 d and oxygen 2 p states are simply reviewed. Then, we mainly focus on the perspective of the development direction of modern SXS techniques. Although the true power of recently developed high efficiency mapping of resonant inelastic X-ray scattering(m RIXS) has been apparent for materials and chemistry studies, great challenges remain for mRIXS spectroscopic interpretation, and the understanding of the battery materials on novel redox activities remains elusive.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CB921904 and 2012CB927402the National Natural Science Foundation of China under Grant Nos 11074142 and 11021464+1 种基金the Key Project of Chinese Ministry of Education under Grant No 309003the Tsinghua TNList Cross-discipline Foundation
文摘Structural and magnetic properties are investigated for Fe1-xMnxV2O4 （0≤ x ≤ 1） spinels. As orbital-active Fe^2＋ is substituted with Mn^2＋, the cubie-to-tetragonM transition TsI and the tetragonal-to-orthorhombic transition Ts2 gradually decrease. These structural transitions originate from the Fe^2＋ ferro-orbital order （F-OO）. Below Yafet-Kittel （YK） magnetic transition TN2, V^3＋ orbital order （V-OO） plays an important role on global structure. Here x = 0.6 is a critical point. Fe^2＋ F-OO and V^3＋ F-OO coexist for 0 ≤ x ≤ 0.5. For x≥ 0.6, the orbital pattern of V^3＋ is antiferro （AF）-00, and Fe^2＋ F-OO disappears. Structural transition Ts3, accompanied by YK magnetic transition TN2, decreases initially, and then increases at x = 0.6. A scenario for the complex phase diagram arising from the cooperation or competition of Fe^2＋ and V^3＋ orbitals is proposed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11474273 and 11634003the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2017154
文摘We investigate the electronic structures and phase stability of ZnO, CdO and the related alloys in rocksalt（B1）and wurzite（B4） crystal, using the first-principle density functional theory within the hybrid functional approximation. By varying the concentration of Zn components from 0% to 100%, we find that the Zn_xCd（1-x）O alloy undergoes a phase transition from octahedron to tetrahedron at x = 0.32, in agreement with the recent experimental findings. The phase transition leads to a mutation of the electron mobility originated from the changes of the effective mass. Our results qualify Zn O/Cd O alloy as an attractive candidate for photo-electrochemical and solar cell power applications.
基金This work was supported by the National Natural Science Foundation of China (Nos. 30171070 and 30371632)
文摘To determine the structure of o-methylisourea for instructing its application and factory production, crystalline o-methylisourea hydrosulfate was synthesized in this paper by methylation of urea with dimethylsulfate, followed by acidification in 53% yield. Its single crystal prepared from 95% ethanol is determined by X-ray diffraction analysis. The crystal is of monoclinic, space group P21/c with a = 8.5330（10）, b = 7.0548（9）, c = 11.6764（14） A°, β = 95.429（2）°, Mr = 172.16, V= 699.75（15）A°^3, Dc = 1.634 g/cm^3, Z = 4, F（000） = 360 andμ（MoKα） = 0.435 mm^-1. Of 1511 unique reflections, 1294 is gotten （I 〉 2σ（I））. The structure was solved by Fourier method and refined to R = 0.0438 and wR = 0.1209. The crystal structure shows that o-methylisourea combines with bisulfate via the intramolecular hydrogen bond between N（2）-H（4） of o-methylisourea and O（2） of bisulfate. As a result, the molecular structure is [H2NC（OCH3）NH2]HSO4 and the formula is C2H8N2O5S or C2H7N2O·HSO4 but not H2NC（OCH3）NH-HSO4 or H2NC（OCH3）NH·0.5H2SO4.
基金the National Natural Science Foundation of China(No.20132020)
文摘In this paper, 5＇-O-tosyl-2,3＇-anhydrothymidine has been synthesized and its crystal structure was analyzed. The crystal belongs to the triclinic system, space group P1, with a = 5.397（2）, b = 6.1886（18）, c = 3.507（5）A, α = 87.74（2）,β = 89.84（4）,γ = 73.79（2）°, C17H18N2O6S, Mr = 378,39, Z = 1, V = 432.8（3）A^3, Dc = 1.452 g/cm^3, F（000） = 198 and Flack = -0.11（14）. No intermolecular hydrogen bonds exist in the crystal, and the angle between benzene ring and pyrimidine planes is 32.23°.
基金the financial supports from the National Natural Science Foundation of China(No. 20972142)the State Key Laboratory of Bio-organic and Natural Products Chemistry,CAS(No.08417).
文摘The building block of N-alkyl derivative of allosamidin（chitinase inhibitor）,4,6-O-benzylidene-N-octyl-D-allosamine hydrochloride was stereoselectively synthesized in two steps under mild conditions.Nucleophilic addition of octylamine to 2- oxoglucopyranoside gave a‘carbonyl group transfer＇ product in 62%yield.Subsequent stereoselective reduction of newly formed C=O with NaBH_4 produced title compound in 75%yield.X-ray diffraction analysis indicates the title compound adopts syn 1,2,3 stereochemistry and chair-chair conformation.The crystal structure is stabilized by hydrogen bonds.
基金supported by the National Natural Science Foundation of China(21002006,20452002)Special Program for Key Basic Research of the Ministry of Science and Technology,China(2004-973-36)~~
基金supported by the National Natural Science Foundation of China (Grant Nos 10574096 and 10676025)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No 20050610010)the Scientific Research Foundation of Young Teacher of Guizhou Normal University, China
文摘The splitting of potential energy levels for ground state X^2∏g of O^x2 （x = ＋1,-1） under spin-orbit coupling （SOC） has been calculated by using the spin-orbit （SO） multi-configuration quasi-degenerate perturbation theory （SO-MCQDPT）. Their Murrell-Sorbie （M S） potential functions are gained, and then the spectroscopic constants for electronic states 2^∏1/2 and 2^∏3/2 are derived from the M S function. The vertical excitation energies for O^x2 （x = ＋1,-1） are v[O2＋1^（2∏3/2→X^2∏1/2）] =195.652cm^-1, and v[O2^-1（2^∏1/2 →X^2∏3/2）] =182.568cm^-1, respectively. All the spectroscopic data for electronic states 2^∏1/2 and 2^∏3/2 are given for the first time.
